Field of the Invention
The present invention relates generally to livestock feeders. In particular, the present invention relates to a livestock feeder that can be used as a gravity flow feeder for small animals, and as a mechanical rotary feeder for larger animals.
Description of the Related Art
The method of raising pigs has changed significantly over the past 40 years. Prior to the large pork production units of today, pigs were raised on the many small family farms that populated the United States of America. These small pig raising farms were diversified with many types of animals which allowed the farms to raise their own grain and grind some of that grain into feed for the farm animals. The animals included on most farms were chickens, cows, beef animals, and pigs. This diversification ensured that everything on the farm had a use and most waste materials were consumed by one type of animal on the farm. The farm animals typically lived in small outdoor sheds and occasionally in pens with other types of farm animals.
Over the years, these diversified farms began to change into specialized farms. Many began to cut down on the number of different animals raised in lieu of larger numbers of the same type of animals. Some farms selected cattle, some selected chickens, and still others chose swine. Most of the changes depended on the producer's interests, resources, and animal facilities. In the 1970's the trend in the pork industry was to increase the number of breeding female pigs on the farm and place the birthing pigs (farrowing) into buildings where the animal care could be more centrally provided. The baby pigs were then moved outside to grow until they were taken to market. More changes in the pork industry continued the following years. Eventually pigs were moved into buildings designed and ventilated for their specific age.
There are four types of buildings commonly used in the production of pork. The first type of building is the Breeding/Gestation building where the female pigs are bred and allowed to grow during the gestation period. The gestation period of a pig is typically three months, three weeks, and three days.
When the gestation cycle is completed, the female pigs are moved to the second building type. This building is used for birthing, or more commonly known as farrowing, of the females. This second building type is known as the Farrowing building. The female pigs (gilts/sows) are placed into a stall that prevents movements during farrowing and protects the baby pigs from being crushed to death as a result of the mother laying on them. The time between farrowing and weaning the baby pig is typically 21-28 days depending on the producer. The baby pigs will begin eating small amounts of dry solid feed during this lactation period. The feed is usually placed on a flat tray or a small self feeder.
The baby pigs are weaned from the mother at approximately 21-28 days of age. The mother (sow) is returned to the Breeding/Gestation building while the baby pigs are moved to the third type of building known as the Nursery. The nursery pig will typically be approximately 4.5-7.0 kg in weight at weaning and will be placed into larger pens with several other baby pigs from different mothers. These nursery pigs are fed solid feed through the use of small feeders that are filled with a specialized type of feed that matches their digestive development. There are usually three different formulations of feed provided to the nursery pigs as they grow to about 16-22 kg.
When the nursery pigs reach the desired weight, they are moved to the fourth type of building known as the Finishing building. The nursery pigs will remain in finishing pens from their entry weight of 16-22 kg to the market weight which is approximately 127 kg. The length of time for a nursery pig to reach market weight depends on many factors. Some of these factors include the quality of feed, the proper phase in which different feeds are introduced, building ventilation, water supply, disease, equipment, and animal handling techniques. Each of these factors has growth consequences when problems arise and the result is usually seen in the days it takes for a nursery pig to reach market weight.
Animal handling techniques and animal movements from one building to another create stress in nursery pigs that result in slower growth. The animal stress can also cause sickness, lack of appetite, and general disorientation which compounds the delay in animal growth and development. Special care must be taken when handling animals to prevent these effects from occurring.
Pork production in the 1990's saw further changes in the way swine were raised. Farms grew even larger and became known as farrow-to-finish farms. However, since the farms were becoming much larger with increasing animal population on each farm, major concerns about diseases arose. The concern was that since there was a large population of swine in a concentrated area, if a disease outbreak occurred, it could quickly doom the entire swine population. The solution to the disease concern was to begin separating the animal population and place them in different geographical locations that provided a single type of growth management. Therefore, the farms were separated into Breeding/Gestation/Farrowing farms (Sow Farms), Nursery farms, and Finishing farms all located at different geographical sites. This became known as three-site production.
The three-site production arrangement created a different problem. Baby pigs must be transported from the Sow Farm to a Nursery site and when the appropriate animal weight is reached the nursery pigs are moved to the Finishing site. Sometimes these sites are many kilometers apart and the transportation time and conditions (weather, trailer design, temperature, etc.) create much animal stress. The result of the animal stress is poor growth for a certain period of time until the pigs settle down and become acclimated to their new surroundings.
Three-site production continued to be used until the early 2000's when the Nursery and Finishing sites were combined to form what is known as Wean-to-Finish farms. The change to Wean-to-Finish farms reduced the number of production sites from three to two and reduces the animal stress as a result of the animal handling and movement. This Wean-to-Finish process allowed producers to place their Breeding/Gestation/Farrowing site, known as a Sow Farm, in mild climates while placing the Wean-to-Finish farms in geographically located sites that are close to the production of feed grains. These geographical areas in the United States are typically in Iowa, Illinois, and Indiana where corn production is greatest. The reason for locating Wean-to-Finish farms in corn producing areas is to reduce the amount of transportation costs associated with moving feed.
Feed consumption of swine is very significant, especially as the pig approaches market weight. The feed costs are approximately 70% of the cost to produce pork. Any reduction in feed costs directly impacts the profitability of a pork producer. Likewise, the faster the weaned pigs grow to market weight, the better the growth efficiency is of the operation. Therefore, both feed costs and animal growth are the most important factors in a profitable pork operation.
The amount of feed that a growing pig requires is significantly increased as the animal approaches market weight. However, the feed efficiency of a pig decreases as it grows resulting in increased feed consumption with less animal weight gain. The larger the pig grows, the more it eats, but less of the feed consumed is turned into marketable meat weight.
Another aspect of a growing pig is that the pig becomes more and more interested in rooting, or playing, with anything that moves. This is a natural instinct for swine. They forage for food at ground level and will use their massive strength to move obstacles that are in the way. When eating, pigs usually sort the main feed component from the dirt and chaff by blowing and rooting. Therefore, if there is a large pile of feed available, a pig will scatter the feed and trample most of it in an effort to locate the best feed materials.
The design of feeders used in providing feed for growing pigs is very important when considering the factors presented earlier. The traditional pig feeder is designed where bulk feed is stored in a hopper above some outlet openings located in the feed trough. As the feed is removed from around the opening, additional feed flows from the hopper to fill the space where the feed has been removed. Gravity is the mechanism that causes this feed to flow from the hopper to the feed trough. This traditional pig feeder has become known as a gravity flow feeder. Therefore, the gravity flow design allows feed to always be present when the pig enters the feed trough area. The amount of feed flowing from the feed hopper to the feed trough is regulated by adjusting a slide gate that covers the opening in the feed trough. When the pigs are small, the opening will be large, allowing more feed to be presented to the pigs. As the pigs grow, the adjustment gate is closed to restrict the feed flow from becoming too great and allowing the pig to sort and waste the feed. Timing of this feed adjustment is crucial and often difficult to maintain.
FIGS. 8 to 10 show a typical gravity flow feeder 100. This type of feeder 100 has a feed hopper 101 that is connected directly to the feed trough 102 through an opening 103 at the base of the feed hopper 101. The feed flow through the gravity flow feeder 100 is shown in the cross section view of FIG. 10. The feed is stored in the feed hopper 101 and flows out of the bottom into the feed trough 102. The feed flows through feed adjustment doors 104 that restrict feed flow into the feed trough 102. The gravity flow system works very well when animals are small and do not consume much feed, but as the animals grow, the feed adjustment doors 104 must be closed to prevent excess feed from flowing from the feed hopper 101 into the feed trough 102. Any excess feed will be wasted by larger animals as a result of the animal's natural rooting and sorting behavior. Therefore, when the feed adjustment doors 104 are closed and restrict feed flow, the animal's become hungrier, more aggressive, and do not grow as intended. The typical gravity flow feeder works very well for small animals, but has serious performance deficiencies as the animals grow larger and stronger.
Osborne Industries, Inc. recognized the importance of hog feeder design and developed a mechanical rotary feeder known in the industry as the Big Wheel® Feeder (U.S. Pat. No. 6,199,511) to overcome the two primary factors outlined earlier. The Big Wheel® Feeder operated on a mechanical flow principal where the pig's natural rooting instinct is utilized to operate the feeder. Since the feeder is round in design and has a rotary feed wheel that transports the feed from the feed hopper to the feed trough, it constantly mixes all the feed in the trough, so that sorting and feed wasting is minimized. The Big Wheel® Feeder only requires a one-time adjustment to accommodate the type of feed quality and coarseness of feed grind, so that the feed flows properly through the feeder's mechanical delivery system.
Mechanical rotary feeders have been manufactured in several different sizes to fit the size of pig being raised. Nursery feeders and finishing feeders were designed to meet the needs of the respective pig size and weight. This rotary feed delivery became the feeder of choice for pork producers in the 1990's, owing to its substantial reduction of feed waste and improved feed efficiency. The use of gravity flow type feeders decreased as feed costs increased and producers strived to reduce the number of days it takes to raise a baby pig to a market sized pig.
The current swine production process (sow farms and wean-to-finish farms), which has been described earlier, has caused several problems for the design, operation, and upkeep of pig feeders. The three-site production process benefited greatly from the mechanical rotary feeder design invention. However, as the production process has been changed to Sow Farms and Wean-to-Finish farms, problems with pig feeders has been placed back into focus.
The primary problem is designing a pig feeder that is a one-size-fits-all solution. The pig feeder design must feed growing pigs from wean size (4.5-7.0 kg) to finish size (127-130 kg) while meeting durability, ease of use, reduction of feed waste, and optimal feed delivery requirements. The two types of pig feeders each have their strengths and weaknesses in meeting these requirements.
The gravity flow feeder design is optimal in the starting of weaned pigs because the feed is always present in the feed trough and there is no action or movement required by the baby pig. However, as the baby pig grows, the gravity flow feeder design is quickly overwhelmed with the behavior of a growing pig and adjusting the feed flow becomes a significant challenge. The feed flow adjustment is critical to provide enough feed to enhance growth, but not so much that waste occurs. There is a very fine line in making this adjustment and normally the adjustments are not appropriately made, resulting in either under-nourished pigs or excessive feed waste. The amount of feed wasted by growing animals is very costly and creates waste management challenges. Many Wean-to-Finish farms have hired personnel to travel from farm to farm to make these timely adjustments, however, disease concerns and lack of skilled personnel are preventing best practice procedures from being fully executed.
Mechanical rotary feeders are optimal on the larger growing side of the finishing pig owing to the pig's natural behavior, superior feed flow control (auto regulating), and consistent feed mixing to reduce sorting and fouling of feed.
The major disadvantage of the mechanical rotary feeder design is that the feeder design requires the pig to be of sufficient weight and size to move or operate the feed wheel which mechanically moves feed from the feed hopper to the feed trough. If the feed wheel is not moved, no feed will be delivered to the feed trough and the result will be under-nourished pigs. This is why the mechanical rotary feeder design was constructed to match the animal size and weight. It is possible to use a small mechanical Rotary feeder designed for baby pigs weighing approximately 7 kg and feed the larger growing pigs weighing 50-100 kg. However, the feed trough size will eventually be too small to accommodate the head size of the growing pig (100 kg and above), and the feed hopper capacity will be less than required to feed the number of pigs that may be eating.
If a mechanical rotary feeder designed for finishing pigs (minimum pig starting weight 20 kg) is used to start the weaned pig at a weight of 7.0 kg, the weaned pig will have insufficient strength to move the feed wheel and dispense feed into the feed trough. Since the smaller weaned pigs are unable to operate the larger mechanical rotary feeder, they will be under-nourished to the point of death, if no other attention is provided.
There is a need in the industry for an improved livestock feeder that can be used in a wean-to-finish swine operation.